People who only sleep 2-4 hours a night were about 75 % more likely to be obese than normal sleepers.

People who slept 5 hours a night were 50 % more likely to be obese.

People who slept 6 hours a night were found to be were about 25 % more likely to be obese.

Long sleepers who sleep for more than 10 hours were 11 % less likely to be obese.

Although the exact mechanism is unknown and the results are only associations, not a cause an effect, the study seems to suggest that having more sleep provided a protective effect reducing the risk against obesity.

It is equally likely that obese people tend to sleep less and this produces the association found in the study.

These results generally confirm other studies of adolescents and children that show a similar relationship between sleep and obesity for these groups.

There are various theories to explain this that range from a tendency for sleep deprivation to encourage poor diets and binge eating, lack of exercise, changes to the body clock and the way the body processes food and hormone changes.

The amount of sleep may impact various hormones that affect food intake and appetite, such as "leptin and ghrelin," according to this research.

Various researchers have found that students deprived of sleep tended to be

were less alert and slovenly

hungrier

had increased amount of body fat, especially belly fat

ability to metabolise sugar was reduced

had lower levels of the hormone leptin (a protein manufactured by your body’s fat cells). People carrying higher fat loads tend to have higher the level of leptin in their bloodstream. Researchers are still unclear exactly what leptin does in the body but think it may help generate feelings of satiety and fullness after eating or it may affect appetite.

had higher levels of ghrelin which is a hormone that triggers hunger. Lack of sleep induces hunger and encourages people to eat more.

people tended to be fatigued and this lead to them wanting to eat to get the sugar fix.

A major Australian study examined the relationship between sleep and obesity for children aged 5 to 15 years. The association between short sleep and obesity was strongest for younger children, especially boys.

The study showed that the association was insignificant for children aged 13-15. The study also showed that the impact of short sleep was compounded by low levels of physical activity.

The findings were that the preference for snacking, skipping breakfast, fatty food and eating out by people who were sleep deprived only partially explained the association with obesity. The researchers suggested that other things, including physiologic mechanisms and hormones, may explain the association between sleep and obesity.

A Swedish research study found that sleep-deprived young men consumed about the same amount of food as a control group who slept normal hours, but burned between 5-20% percent fewer calories than the well-rested group.

The sleep deprived young men were more fatigued and exercised less that the group who slept more.

Another study of 30 men and women divided into two groups, who had controlled amounts of sleep of 4 and 9 hours, showed similar calorie consumption rates of about 2,600 per day. But the sleep-deprived group, when allowed to feed themselves ate about 300 more calories on average than when they had been sleeping normally.

This meant that the sleep deprivation increased the risk of obesity. The subjects in this study reported that they felt less energetic and more sluggish after a few days on the sleep-deprivation schedule.

One possible explanation is that when people are tired they become vulnerable to making poorer healthy eating decisions.

This especially applies to people who are on diets or who are trying to watch what they eat.

Conclusion

If you are trying to control your weight or you are dieting, it would be helpful not to be sleep-deprived. Getting enough sleep is probably an essential part of being healthy.

Find out if lack of sleep affects weight loss programs here. Source: Public DomainHaving a good night's sleep keeps you on an even keel so you can maintain the discipline needed to keep on your weight loss plan. Source: Public DomainFind out if lack of sleep affects weight loss programs here. Source: Public DomainLack of sleep can lead to poor diet and bade eating habits. Source: Public Domain